There's about six endings available in Cyberpunk 2077, depending on the choices you make during crucial dialogue scenes and within side quests. During Act 2, it's recommended to complete as many side quests as possible to ensure you have the maximum amount of choices at your disposal once you actually go on to meet Hanako at Embers.
Some of the side quests have a very strong effect on the ending of the game, while others just make smaller appearances in various forms, either during the ending scene or the end credits. Without engaging in any side quests, your options will be limited to either trusting Arasaka to handle the situation or to simply end things on your own term. Here's which quests to complete at the very least to open up your choices. Warning, spoilers ahead!
The Peralez Family Story
Starting off with a minor one, the Peralez couple will contact you sometime during Act 2 to ask for your help in an investigation. This will put you in touch with River Ward as well, which will help you finish his storyline later. The Peralez initially want a simple investigation into the death of the previous mayor, but they will contact V later on for more pressing concerns.
The actual main quest of the Peralez couple has you investigate their lavish penthouse for potential signs of intruders or burglars. It turns out that the family has been under close surveillance for a long time, but an unknown entity that could either be a corporation, their rivals or even a rogue AI as suggested by Johnny.
As you advance through the quest, it becomes a possibility that Jefferson's wife Elizabeth Peralez is actually in on this whole mission and seeks to use mind control on her husband. With that, you're given a choice on what to tell Jefferson himself when you eventually meet him.
As a result, you will receive a call from the Peralez during the end credits, and even later down the line in Act 2 depending on the choices you made. It's unclear what happened to the two of them, but if you let Jefferson know he was being watched and controlled, he will come to even suspect his own wife as well.
River's Story
River Ward is an NCPD detective you'll likely meet during your dealings with the Peralez couple, a set of quests which will become active once you're deep in Panam's side quests. After helping him investigate the fate of the previous mayor, River will take a liking to V and call them back for some help regarding a personal matter.
River's side quest is quite dark and involves rescuing his missing nephew Randy from the claws of a child abductor. By examining the dreams of the abductor through a braindance sequence, River and V will have the chance to determine where Anthony, the criminal, could potentially still be holding Randy and the rest of the abducted teens.
It's important to find all possible clues to be able to narrow down the right farm. Once you arrive to Edgewood Farm, prepare to disarm a bunch of turrets and landmines which are scattered around the perimeter. You can get inside through several ways, including the roof which has a hole in it.
Inside, you'll find Randy and the rest of the kidnapped teens. After rescuing them, and finishing the quest line with River, as well as romancing him, River will most likely appear in the end credits scene in a call. If he was contacted during Act 3 and V is allowed to return to her life in Night City, River will be at V's side and is one of the few NPCs who will not leave Night City.
Judy's Story
Judy Alvarez is met already during Act 1, so getting to know her won't be a challenge. However, how you handle things afterwards will determine whether or not Judy will stick around with you until the end. Make sure to help her find Evelyn Parker during Act 2 and try to be compassionate and kind towards her, even when she's untrusting of you.
Judy's story culminates in getting revenge against Clouds, the club that essentially failed to save and protect Evelyn Parker. Help her achieve her revenge by siding with Judy and taking down Maiko when she turns on you upon threatening the Tyger Claw bosses.
The final step in Judy's story line is her romance quest Pyramid Song, which will have you join her for a dive within the nearby dam. Make sure to scan as many clues from her past as possible during the dive, and if you're playing a female V, choose to romance her later on once you've returned to the shack for the night.
Judy will appear in the end credits no matter what ending you chose if you completed her quest and romanced her. If you chose to call her before the final quest, and if V is allowed to return to her life in Night City, then you'll wake up next to Judy at V's new mansion at the top of the city. Unfortunately, Judy has set her mind on leaving the city, a decision which won't change even at high affinity levels.
Kerry's Story
Kerry Eurodyne is Johnny's former band member and one of the few people that remain of the original Samurai group. Johnny will have you contact him by sneaking into his mansion in North Oak, where you'll need to prove to him that Johnny's living inside your head.
Kerry's quest line is perhaps the tamest of all the romance quest lines. Many of his concerns have to do with music and his own career. Join him and the rest of the band for a final Samurai concert where Johnny will take over V's consciousness, after which Kerry will contact you for a few additional quests involving the girl group Us Cracks.
After helping him meet the Us Cracks girls, Kerry's quest will culminate in a trip on a lavish yacht that travels past Night City's shore. Help him destroy the yacht thoroughly, and if you're a male V, you can make a romantic advance here, as well as previously when meeting him at a club with Us Cracks.
Kerry will also call you during the end credit scenes, but much like River and Judy, he can also appear at V's mansion if you choose to call him before the final quest in Act 3. Kerry, just like River, has no plans to leave the city and will remain by V's side even as they go on their final mission, if V was allowed to come back to Night City.
Johnny's And Rogue's Story
The romance options aside, one of the most important quests is that of Johnny's and Rogue's. Johnny is basically the second main character of the game, so ensuring that you have a good relationship to him by the time Act 3 rolls around is absolutely crucial. In order to do so, you need to complete a few of his personal quests.
Make sure you collect all of Johnny's clothing items, his gun, as well as his car. Collecting most of them will still raise your affinity level with him enough to unlock this ending. When Johnny asks you for favors, such as contacting Kerry and going on a date with Rogue, make sure to agree.
As for top fixer Rogue, if you've completed Blistering Love and allowed her and Johnny to go on a date, she will become an option for the final mission. At the rooftop when V must make a decision on how to handle things, choose "I think you and Rogue should go", which will essentially have Johnny take control of V.
Once inside Mikoshi, you have another choice to make. You can either have Johnny sent back to Night City to live in V's body, or allow V to live out their final days with their loved ones. With Rogue gone, V will now be the top personality at the Afterlife.
Panam's Story
Panam Palmer and her nomads are another significant part of the game and its ending. You'll meet her shortly before chasing after Anders Hellman and a Kang Tao vessel, thanks to Rogue. Panam's quest line is incredibly long but quite linear, and will have you complete personal missions for you and helping the Aldecaldos.
Finishing this quest line and reaching Queen of the Highway with Panam is probably the most important quest to finish before entering Act 3. That's because the Aldecaldos are now in V's debt and will become an option to call up when you find yourself at the rooftop with Johnny and have to make a decision.
If you choose the Aldecaldos over Johnny and Rogue, and don't wish to trust Arasaka or end things on your own, Panam and the rest will help you enter Arasaka and more specifically Mikoshi. However, in the process you will lose Saul, when you enter the fight with Adam Smasher.
Choosing the Aldecaldos will also allow you to leave the city with the nomads and Panam, rather than staying behind. If you chose Johnny and Rogue instead of the Aldecaldos, but decided to call Panam instead and romanced her, she'll be at V's mansion and announce that she's leaving with the rest of the nomads.